FR2483837A1 - MACHINE FOR SLICING BREAD - Google Patents

Abstract

THE SLICING BREAD IS MOVED BY A CARRIAGE 13 AGAINST SEVERAL VERTICAL BLADES 22 WITH ALTERNATIVE MOVEMENT 37 USING AN ENDLESS CHAIN 16 MOVED BY A M1 DIRECT CURRENT MOTOR WHICH IS ASSOCIATED WITH A CURRENT LIMITER WHICH, FROM D 'A CERTAIN CURRENT, LIMITED TO THIS VALUE, WHICH REDUCES THE POWER COMPARED TO THAT WHICH WOULD BE NECESSARY AND, THEREFORE, THE FEEDING SPEED OF THE TROLLEY 13 AGAINST THE BLADES 22 WHEREAS AN AUTOMATIC ADAPTATION OF THIS SPEED TO THE RESISTANCE OPPOSED BY THE BREAD, WITHOUT THE USE OF FRICTION COUPLING.

Description

The subject of the invention is a machine

slicing bread, commonly called slicer,

taking motors for the drive of a blade holder

  and a drive chain for a translating carriage

  tion which carries the bread to be cut into slices and whose speed of advance is controlled automatically according to the ease of slicing the part of the bread being cut6. In such machines, a motor running at constant speed is used and a friction coupling is inserted in the kinematic chain.

  to order the advance of the bread (see the request for bre-

German vet No. 2 157 161). The torque transmitted by the ac-

  blow] ement friction is adjustable and must allow a

  adaptation of the advance force to the resistance of the different

re: these kinds of slicing bread. This feed rate control does not meet all needs. Realization of the transmitted torque cannot be done with sufficient precision and it strongly depends on the quality, which varies over time of the coupling elements, which gives rise to undesirable variations. In addition, such a friction coupling occupies a determined place in the slicer which is therefore no longer available for

other important organs.

The main object of the invention is to develop a slicer of the aforementioned type, but offering an advance which can be individually adapted to the resistance.

of each kind of bread.

  According to the invention, this result is made that the reached by le7-. otor of the bread carriage drive chain is associated with a current limiting device acting on the power it absorbs and having the effect of reducing its speed of rotation when the need arises

  power rises as a result of greater resistance

tance encountered by the bread translation carriage.

  The current limit is chosen first so that the current fluctuations in bread resistance do not immediately affect the feed as this could lead to a reduction in the efficiency of the machine. In such cases, the blade holder is capable of flawless cutting of the bread. However, if there is a harder loaf, the power ab-

  absorbed by the engine eventually grows so strong that the cost

rant reaches the setting value of the limiting member.

So if the slicing resistance increases, the motor

  drive can no longer receive additional power

  necessary to maintain the speed of advance, and this results in a decrease in its speed of rotation. An internal advance control is therefore carried out, which takes place very exactly automatically

  based on the engine power draw. This cons-

  measures an accurate measure of the resistance of the bread to

per. Furthermore, the disappearance of the organ which would have been born

  stopping otherwise makes it possible to win in the cinema chain

matic a place which can then be used for other purposes. The current limiting device according to the invention can be integrated simply into the electrical equipment of the machine and, as an electronic component, it

does not occupy a significant place.

The invention also makes it possible to obtain an interruption in the advance of the bread if an annoying object

  the machine or the blade holder reaches the cutting area.

  There is no longer to take into account that the duration of action of the current limiting member, or the magnitude of the drop in speed of the motor, which can be deduced from the power absorbed. On the arrival of the current to the motor is mounted a switch controlled by the absorbed power. In the simplest case, this switch is a thermal circuit breaker which, for heating

  predetermined, interrupts power supply to the motor. The mo-

  The carrier's training driver can then continue

to operate.

  It is further recomEandc oe d oei-

  trust in advance the normal rotzyticn speed dell r.otetur at the end of the pen of bread to be tranobed in order to obtain the optimum cutting speed each time. For this, the smp e is to predict the regulation of the arrival of .- er: ie;} lec, ri.cue to the motor of the drive chain,

this or- is achievable by adjusting the supply voltage

ment, atitr) of this engine.

To obtain automatic working of the machine, it is recommended to provide, on the side of the bread inlet and the side of the slice outlet, at least one limit switch cooperating with the bread cart and the commander reversing the direction of drive and possibly the motor drive speed, to go from advance to reverse and vice versa. 4After operating a start button, the machine then operates automatically. With this in mind, we can predict,

  on the supply side of the machine, several inter-

limit switches only one of which can be returned at a time

  active, and arrange these limit switches at

  different tances of the blade holder. Thus, the bread cart will retreat only the length necessary for the placement of a bread of a given length. For looser breads, a more remote limit switch is used than for narrow breads. We thus operate at

  the better the possibilities of the machine.

  -It is recommended to associate with the drive motor a switch which, in its first position, continuously and cyclically renews the advance and the

  backward movement of the bread cart and pern: and therefore a

  automatic: .ent of the machine. In this case,

breads can be run following the food side

tation of the machine by a chute without the need to gild a new starting impulse

to each bread.

The various manual control devices

  g the solt; advantageously grouped. Their accessibility

  ? ar t-.us the possible sides .'s of the machine is particular-

  re: .- ent lo.ne when placed on a cover above

  of the blade holder. It is then no longer necessary that the ope-

rator occupies a special position in relation to

  the machine for actuating the manual control members.

  We will now give a description

  of a preferred embodiment of the invention, without limiting intention. Reference will be made to the accompanying drawings in which: - Figure 1 is an elevational view

  and in longitudinal section of a slicer according to the invention

tion;

- Figure 2 is the electrical diagram

that of the machine of Figure 1;

- Figure 3 is a graph showing

trant, as a function of time (on the abscissa), the current I

  of the drive chain motor, the speed curve

  tess V of the advance and the temperature curve T (in

  ordered), in an example of automatic disjunction.

  A machine 10 for cutting bread called a slicer comprises a casing 11 serving as a table in which the electrical circuit is arranged, the diagram of which is given by

Figure 2 and mechanical drive means.

  A blade holder 20, surrounded on two sides and on the top of a cover or covering 21 is projecting above the

plan 12 of the table.

  The blade holder 20 is equipped with a plurality of blades or knives 22 placed vertically, with a spacing which corresponds to the desired thickness of the slices. The blades 22 are all arranged on a

  row, but are nevertheless mounted alternately, each

cune by its upper end and its lower end

lower, on one or the other of two frames 25, 26, by means of mounts 25, 24. The upper ends of the two frames 25, 26 are held by flexible arms 27

attached to a cross member 28 to perform pa-

  rallying; the lower ends of these frames are articulated on arms located opposite which are themselves articulated with a pair of oscillating elements

  for this, adjustable fastening means 50 combine

  feels the lower ends of the frames 25, 26 to axes of rotation 51 each passing between the two osjiJants 29 elements. These derr.iers are mounted on a shaft 32 disposed (, between the opposite side walls of the casing 11. One end of these oscillating elements 29 is joined by a connecting rod 33, to a crank plate 34 to which a rotator - L2 communicates a rotational movement in the direction of arrow 36, by means of a belt 55. During rotation 36 of the motor Iv2, the opposite ends of the oscillating element 29 are alternately unlaced up and down,

  so that the two frames 25, 26 move vertically

  slowly and symmetrically to each other. It follows that the blades 22 which are linked to them execute in opposite directions the displacements indicated by a

arrow 37 in Figure 1.

A movable support 13 for the bread to be cut, here called the bread trolley, ensures the movement at speed

adequate bread against the blades 22.

  This bread cart 13 has a structure

comb comprising a plurality of lamellae that a bar

connecting rette 15 connects together and maintains an appropriate spacing so that they are mutually in alignment with the free passages between the blades 22. The bread carriage 13 is connected to an endless chain drive 16 which passes on sprockets 17 mounted

on shafts 18 at the front and at the rear of the casing 11.

  o50 One of these shafts 18 is moved, sometimes in one direction, sometimes in the other, by a motor QI1. When this motor óil rotates clockwise 38, the bread carriage 15 is moved through the chain 16, with a determined feed speed v, against the blades 22. The motor iel can run faster in the counterclockwise anticlockwise 9, so that the speed of recoil of the bread trolley is higher. To control the I1 motor between one

  and the other direction of rotation 38, 39, several interrup-

limiters S1, S2, S3 are mounted on the casing 11,

  their respective actuators 41, 42, 43 inter-

  receiving the trajectory of the bread carriage 13. When the latter encounters one of these actuating members, there is an inversion of the direction of rotation of the motor MN, or else an out-of-circuit thereof. The scheme

of figure 2 helps to understand this mode of operation-

is lying.

  On this diagram, we can see an inter-

starter switch 40 which, via a

thermal circuit breaker 44, is connected to a inlet

  rant 45. The actuating member 46 of the switch

  switching on 40 is carried out in the form of a button.

  Activation of this switch has the effect of activating,

via lines 47, 48 which are connected to it

a relay 50 which closes a holding contact 49 which remains closed as long as the relay 50 is energized. This voltage maintenance takes place as long as the contact is closed

  inside of a switch 51 mounted on the supply line

  ment 48 of relay 50. In this case, it is

  direct current that is used. At a terminal 52, for example-

  ple that of the relay 50, is connected - by a line 55 - the first pole of a bipolar inverter, the other pole of which is connected to the already mentioned line 47 of the switch

40.

  The two movable contacts 55 of the

bipolar pourer 54 are mechanically coupled to be moved simul. aw'men + t. Anar: D. se, they can take either the position 55 represented in solid line, or the position 55 'represented in broken line. In position 55, the current is first sent by the first

  contact to a line 56 at the year is connected a r gula-

  voltage tester 57 whose voltage -e output appearing

  on a line 58 can be real Or an organ 5c- action-

  manually fills. Via a thermal circuit breaker 60 and a current r3e limiter ri the motor i

248383?

denra.lcrle of the chain 16 shown in fig 1

  is racco: rdé. read it 58o By adjusting the tension of the

  ? a'2evu.r 5 '; by means of the regulating member 59, one can -odi-'fier the rotation 38 of the engine LTe1 and consequently adjust the speed of advance v to 1 'to adapt to the kind of dwarf placed in the bread trolley 153 The adjusting member 59 can be pre-taloonn for the various common kinds of bread, which allows an optimal immediate adjustment. The motor current output 1.1 is connected

  0 by a line 62 and the other contact orIane 55 of the in-

  pourer 54 to the aforementioned bypass line 53, The mo-

  tor El is a DC motor, The motor 12 associated with the blade carriers is an AC motor with separate power supply. Its order is made through

another contact (not shown) of the switch-

reverser 54 whose drawing in FIG. 2 is simplified.

The motor I2 is supplied with voltage via a line 63 connected to line 56, and it is provided with a current output 64. The voltage regulator 57

does not act on the 1,12 engine because it drives the holder

  blades 20 at a speed 56 always constant.

  When the bread carriage meets the actuating member 43, of the limit switch S3

  shown in Figures 1 and 2, a pulse of com-

request is sent by lines 65, 66 to inverter 54,

  this yes puts the movable contacts in position 55D represented by

felt in broken lines. The chain drive motor 1iV 16 is then inverted, so that it rotates in the counterclockwise opposite direction 39 indicated in FIG. 1. This occurs because the motor Mi is powered from the power supply 47 by the dOplaced contact 55- 'and the lines 82, 629 and that the current output of this motor passes through the current limiter, 1 and the thermal circuit breaker 60 then by the lines i7 68 going to the other pole of 1 'inverter o the other moved' 55, 'establishes the connection with the current output 52. The voltage regulator 57 is then not

crossed by the current, thanks to which the applied voltage

  quée the motor Ml is greater than during the advance, so that the recoil speed v 'of the bread carriage 13 is greater. The reversing takes place until the actuating members 42, 41 of the switches S2,

  Sl are activated when the bread trolley 13

  against. These switches S1, S2 are spaced from the Dorte-

blades 20 of a distance which corresponds to the different widths of two kinds of bread. Depending on the width of the bread to be sliced, the handle or button 71 is operated by a switch 70 arranged on a line 69 between the two switches S1, S2. In position 72 shown in solid lines in Figure 2, it is the switch S2, corresponding to a narrow kind of bread, which is made active. If the contact member of the switch 70 is at the

  position 72 'shown in broken lines, the interruption

tor S2 is then made inactive and it is the switch S1 which is active, which corresponds to the slicing of a

  wide bread. If there are more than two bread widths different

ferent, it goes without saying that we can then provide a similar number of switches S1,

  S2, etc., arranged at appropriate distances from the carrier

blades 20. Whether the active switch is S1 or S2, the pro-

  cessation is the same when the bread carriage 13 meets the relative actuating member, 41 or 42 respectively: an inversion pulse is sent, by line 75, to the inverter 54 which passes its contact members from position 55 'to position 55, which has the effect

  that the movement v 'of the bread carriage 13 reverses again

calf its direction, the advance v already described then being executed. In this case there is an automatic operation of the machine. The bread cart 13 is moved alternately

back and forth, automatically, between the inter-

switch S3 on the side of the outlet for the bread slices and one of the switches S1, S2 on the side of the inlet of the machine. The bread cart 13 can stay a certain

248383?

nipple? at the extreme points of its course where its

  moving, which can be achieved by delayed organs

dnteuzs or timers which, in this case, can be corsid6r-.s coamne being integrated in the switches S'i, St7? 3 With this mode of automatic work, a new

  sliced bread can be driven automatically-

ment, on the feed side, in front of the cart & bread = i3. The bringing of this new bread can be done, for example, on the side by a carrier, or from above by means of a chute, this bread arriving on the table

12 at the instant when the carriage 13 has reached the point of

version of his movement.

This automatic working mode is

ensured when the mobile contact orpane 74 of an inter-

breaker 75 is in the position visible in FIG. 2. In this position 74 we obtain this result that, if an organ

  manual operation 76 of switch 75 has been ma-

  again, the command impulse coming from the interrupt

  SI or S2 no longer reaches line 77 lying behind

  switch 75. This switch 75 is in the automatic on position described in detail in

what precedes.

However, the switch 75 has another manual actuating member 76 'to cause the displacement of the contact member corresponding to the

  position 74 'shown in broken lines on the figure

re 2. Instead of a separate manual actuator 7e 'one could also provide a joint actuator which, in the event of an operation, would put the

  o0 contact at position 74 and which, in the event of new ma-

noeuvre, would put this contact member in position 74 '.

At position 74 ′ of the contact member inside the switch 75, the condition of channel in "blow by blow" mode is established. According to this mode, the control pulse coming from the switch S; i or S? is transmitted, by a line 90, to the switch then to the line 77, and causes a brief opening of the switch 51 already mentioned. The contact thereof is momentarily placed from the position shown in solid lines to the open position shown in broken lines. This has the effect that the flow of current through relay 50 is interrupted. The contact of

  hold 49 then changes to the cut-off position shown

  felt in Figure 2, which has the effect of interrupting the supply of motors Il and b2. The machine is then

stopped. In this case, the machine stops when the

riot à pain 13 has performed a full recoil V '. This cart

  13 is then in a position allowing intro

bread on the food side. To slice a new loaf, the lever or button 46 of the start switch 40 is actuated again, and a new work cycle begins. This ends automatically after its completion, if the switch

  is in the above position step by step.

Instead of coming from the limit switch S1, S2 is

  located on the machine entry side, the interrup-

  The current of relay 50 could similarly be due to switch S3 on the output side of the

  machine. To do this, simply connect to the interrup-

tor S3 line 90 of switch 75 via line 66

shown in broken lines. In this case, the fixed asset

  sation of the carriage 13 takes place at the end of the advance V,

in the region of the blade holder.

The machine also has an inter-

  emergency stop 78, whose manual actuating member 79 makes it possible to immediately stop the advance v of the carriage

  bread 13. In this case, the contact member 55 of the reverse

  seur 54 is, by a line 80, immediately put in its retracted position 55 ', which has the effect that, as already described,

  the rotation of the F1 motor is reversed in the anti-direction

59 and that the carriage 13 performs its movement of

  recoil v'0 This has the effect that the blades 2: of the

blades 20 are not subjected to the thrust of the carriage 13,

  and that the accidents reported are Tvitrs. Ih low teacher

24e3837

  culable 81 acting on the bread is associated with the blade holder.

  The emergency switch 78 also transmits, by a line 85, a cut-off pulse to an automatic selector switch 759 which ensures that, in the case where the contact member is in position 74

  ending automatic walking there would be an in-

version in position 74 'corresponding to step by step. There is then, whatever the previously adopted operating mode, a stop of the machine at the end of the recoil when the carriage 13 has reached its point of inversion on the side of the input of the machine. As already explained above, the switches S1, $ 2 on the input side are then connected, by line 90e to

the input of switch 75. The actuation of these in-

switches S1, S2 cause the switch-off condition

  re from switch 51 on relay 50 power supply .; The switch 40 at the input is then set to its "READY" position, and the motors Mll, 2 no longer rotate. When retreating vy from the bread carriage 13 it is recommended (although this is not shown in the fibure 2) that the motor I12 of the blade holder 20 is cut off automatically, in order to increase safety and

  reduce energy consumption.

The particular effect of the

current 61 will be explained now with reference to the fi

  gure 3. This limiter 61 does not authorize an increase in

  rant of the motor àrll only up to the value Ig visible in FIG. 3, In time t '- to plotted on the time axis

  which is the x-axis9 there can be fluctua-

  current that result from absorption of power

variable speed by the motor M1 during the cutting of the bread crust without this having any effect on the speed of advance v, which is represented by the curve plotted in

  dashed line 7l V in FIG. 3. Next, in the example

  pie represented by the graph of FIG. 35 a hard part of the bread arrives at the cutting zone of the blades 22, which requires the absorption of a stronger current by the motor Ml. This current must not exceed the limit value Ig, which is reached at a time t 'on the graph. The current limiter 61 does not allow this value to be exceeded, so that the advance speed v then begins to decrease when the power demanded by the motor increases. The advance speed v is notably reduced, as can be seen by the part of the curve in broken lines after the instant t '. At the same time,

  as indicated by the curve T in solid lines, the temperature

  The temperature monitored by the thermal circuit breaker 60 increases.

  The limit temperature is shown in broken lines, in Tg, in FIG. 3. Its value is chosen so that, for a moderate reduction in the advance speed v, the circuit breaker 60 does not yet react. This happens for the duration t "-t'o Then the advance finally became so difficult that, due to the increase in

the absorbed power, the temperature reaches the value-

  limit Tg. This has the effect of cutting off the power supply to the motor Ml, this cut-off being effected by the thermal circuit breaker 60, at the instant t "in the case illustrated by FIG. 5. At this instant, the curve I changes from definitively towards stopping: the current is interrupted at t ", so that the advance speed v is canceled. The motor M1 is stopped, while the motor IM2, not concerned,

keeps spinning.

  After elimination of the obstacle which hinders the advance of the bread, the motor I1 can be restarted by action again, manually, on the member

  resetting 86 of thermal circuit breaker 60. The former

  normal operation can then continue. We can work at constant speed if the power absorbed

does not lead to the Ig value mentioned above being exceeded.

  However, if this limit value is exceeded, the speed-

se of training v is automatically established at the correct lower value, as indicated in the time range t "-t 'for the example of use illustrated in FIG. 3, when the resistance of the bread to the slice

  to <-meorte. -a machine according to the invention therefore starts automatically-

  tick; the correct speed of advance v, even if by m, & - azr'e the organ of râilas: e 59 of the tension regulator 57 was not put in the position appropriate to the bread to be cut. The machine therefore corrects itself by

electrical means.

  In the embodiment described

above, the increase in power for the power

ment of the engine L11 is monitored, and the advance speed IO v is reduced accordingly. Instead of that,

we could also consider controlling the call of the

rant on the supply line 63 of the IV2 motor provided for the movement 37 of the blade holder 20, if this allows better date I: r The laughter of the bread to be sliced to the point

  of its slicing difficulty. A control body

the 1iI2 motor current draw could then

  react on the motor speed control il1 and, finally

Also, completely cut off the power supply when this speed has fallen below a threshold.

lower or when a limit temperature has been exceeded.

  That said, we can still consider

  cases in which significant disturbances appear-

  bations which also make it necessary to cut off the power supply to the N12 motor ensuring movement 37 of the

  blade holder 20. For this, it is sufficient to provide on the rear

  current bank 45 common to the two motors Ml 1, I2 a

  another thermal circuit breaker 44 which, in such conditions

  extreme ticns, reacts finally and cuts off the arrival of

current. In this case, the two motors M, 112 are stopped.

  0 tees. After elimination of the fault, a latching device

* corresponding menL 87 allows you to reset the circuit breaker

  thermor valve 44, after which motors M1, M2 can

resume normal operation.

Finally, as shown in Figure 1,

43 we could also consider bringing together all the

ectio ns: manual operation 46, 79, 76, 76 ', in a conmmun 88 control panel arranged with a good

  accessibility to the upper part of the cover 21. To the or-

  ganes of manual control thus placed one could also add the manual adjustment member 59 of the tension regulator 57. If necessary, one could still put in this place the engagement members 86, 87 of the

  thermal junctions 60 44, so that all the or-

ganes of manual control would be placed at the top of the machine where they would be of equal

accessibility from all sides.

REVE1 'ICATIONS

1) Bread slicing machine with two motors, one for driving a blade holder and the other for driving a chain coupled to a bread cart which carries the bread to be sliced and whose speed of advance is automatically controlled according to the ease of cutting the bread in the region being sliced, this machine being characterized in that the motor (Ml) driving the chain (16)

  is associated with a current limiting device (61) in operation

  tion of its demand for powers whose effect on

  rotation speed (v) of this motor (ML) is of the re-

  decreasingly when the demand for power

  this rises as a result of greater resistance encountered

taken in advance by the bread trolley (13) I 2) Machine according to claim 11, characterized in that the supply of electrical energy to the motor comprises a switch (60) which reacts to the due (t "-t ') of activity of the current limiting member (61) and / or the extent of the fall in the speed of

rotation (38, V) of the motor.

  3) Machine according to claim 2t characterized in that the switch is constituted by a thermal circuit breaker (60), 4) iMachine according to any one

  of claims I to 35 characterized in that the back

v6e of electrical energy to the drive chain motor

  nement (16) is adjustable, by acting on the supply voltage

denies this engine.

  5) Machine according to any one of

  Claims 1 to 4, characterized in that at least

  a limit switch (S19 S29 S3) is associated with the bread trolley (13), also white on the side of the

  bread only from the outlet side of the slices, this interruption

restrictor cooperating with the carriage (13) and controlling

the drive direction (38, 39) and the drive speed

engine (Ml) to cause the advance to pass

(v) at recoil (v '), or vice versa.

  6) Machine according to any one of

  claims I to 5, characterized in that several

  limit switches (Sl, S2) of the same category are associated with the carriage (13), on the bread feed side, and are at different distances from the blade holder (20), only one of them ( SI, or S2) being made active

depending on the use case.

7) Machine according to any one of

claims 1 to 6, characterized in that the control

  chain drive motor (1MI) (16) is associated

  linked to a switch (75) including a first position (74)

has the effect that the bread carriage (15) repeats cyclically-

its advance (v) and its retreat (v '), and whose other position (74') has the effect that this carriage only executes

an advance and a retreat.

8) Machine according to any one

  of claims I to 7, characterized in that the or-

manual control handles (46, 59, 76, 76 ', 71) for the

  breakers or switches, and the ma-

  china (10) are placed on a cover (21) above the

blade holder (20).